The investigation into the August 4 Air India Phuket-Delhi flight incident has taken a new turn after a post-flight maintenance report mentioned that the aircraft recorded three hydraulic system low-pressure
warnings followed by an autopilot disconnection during the journey, India Today reported, citing sources familiar with the probe.
The report relates to Air India flight AI2379, operated by an Airbus A320 aircraft bearing registration VT-EXO.
The aircraft was flying from Phuket to Delhi when it experienced a sudden altitude variation of around 300 feet during cruise before stabilising and landing safely in the national capital.
Three Hydraulic Alerts Recorded During Flight
According to the maintenance document cited by the report, three hydraulic system low-pressure warnings were recorded within a very short period during the flight.
The alerts involved the aircraft’s green, yellow and blue hydraulic systems.
The maintenance report was prepared after the aircraft landed in Delhi, India Today reported.
ALSO READ | Air India Phuket-Delhi Flight: Airline Said Turbulence, Then Changed Report To Hydraulic Faults. What Documents Say
The document also recorded other technical warnings, including alerts relating to emergency exit doors and other aircraft systems.
The sequence of warnings was a part of the investigation into what happened aboard the flight.
Autopilot Disconnected After Hydraulic Alerts
The report mentioned that an autopilot disconnection warning was recorded shortly after the three hydraulic alerts.
A second autopilot-off warning was logged later in the flight.
According to sources cited by the publication, this could indicate that the autopilot was restored after the initial disconnection and subsequently disengaged again.
Sources were quoted as saying that investigators were examining whether the sequence of hydraulic warnings, autopilot disconnection and subsequent system messages had any connection with the turbulence event and the aircraft’s approximately 300-foot altitude variation.
The post-flight maintenance record, according to the report, had also been shared with the Directorate General of Civil Aviation (DGCA) and the Aircraft Accident Investigation Bureau (AAIB).
Aircraft Continued Flying For Around 1 Hour 20 Minutes
The timings mentioned in the maintenance report indicate that the aircraft remained airborne for around 1 hour and 20 minutes after the initial hydraulic warnings were recorded before landing safely in Delhi.
The August 4 incident involved 137 passengers, including three infants, and eight crew members, according to the AAIB.
The probe agency said 20 passengers and four cabin crew members suffered injuries.
The aircraft later stabilised and completed its journey to Delhi.
AAIB Examining Flight Data And Maintenance Records
The AAIB said that it is systematically collecting, preserving and examining all relevant technical, operational, medical and human-factor evidence connected to the incident.
“This includes examination of the aircraft and its systems, recorded flight data, relevant operational and maintenance records, medical information, and interviews with persons concerned,” the agency said.
“All material evidence will be examined in its entirety before any conclusions are drawn,” it added.
Officials from France’s Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile (BEA) and technical representatives of Airbus are assisting the AAIB with the investigation.
The agency said it would issue preliminary findings within the stipulated timeframe in accordance with applicable provisions and International Civil Aviation Organisation (ICAO) protocols.
AAIB Warns Against Drawing Premature Conclusions
The AAIB specifically cautioned against drawing conclusions from isolated pieces of information while the investigation remains underway.
“The investigation is independent, evidence-based and comprehensive, and no inference regarding the cause of the occurrence should be drawn from any isolated piece of information while the investigation is in progress,” the agency said.
The probe agency said its objective is to determine the circumstances and contributing factors relating to the occurrence and identify appropriate safety measures to prevent a recurrence.
Pilot Tested Positive For Marijuana In Confirmatory Test
The incident was also being investigated separately in connection with the flight crew’s psychoactive-substance screening.
According to PTI, the pilot-in-command of AI2379 tested positive for marijuana in a confirmatory screening test. Both pilots had undergone the prescribed psychoactive-substance screening.
The Civil Aviation Ministry had earlier said the pilot-in-command’s initial screening result required confirmatory testing and that the sample had been sent to a designated laboratory for analysis.
Pending completion of the investigation and testing process, the DGCA has taken both flight crew members off the roster.
The AAIB has said further information will be placed in the public domain at the appropriate stage of the investigation.
ALSO READ | Air India Phuket-Delhi Pilot, High On Marijuana, Was Also On Sleep Medication; Had Trouble Resting Before Flight
